Objective To prepare a radiofrequency (RF) ablation probe guided by endoscopic ultrasonography (EUS) and to evaluate its efficacy and safety. Methods A modified 19-gauge needle ( Olympus) was used, which was electrically insulated with shrink tubing, with the tip of lcm naked. The insulation was tested, and the current signal was stable. Three rabbits were anesthetized with 8% chloral hydrate ( 3 ml/kg) intraperitoneally, fixed on the dissecting table. A standard neutral pad was applied to the thigh of the rabbit to complete the electrical circuit, both the pad and the needle electrode connected with RF generator. After anesthesia was ready, the needle was advanced through the gastric wall into the liver. Ablations were performed three times in the same zone. Extent and tissue lesion were measured after ablation. Results Ablation could be successfully performed by the needle electrode, with brown lesions surrounded by normal hepatic tissue. The mean diameter of the ablated zone in the liver was 1.0 cm× 1.2 cm. After ablation,specimens along the passage were subjected to NADH staining, and no lesions were found. HE and NADH staining showed no viable cells in the central ablation area. Conclusion With the advance of the technology and selection of materials, an EUS-guided needle electrode can be made. This preliminary animal trial demonstrates that radiofrequency ablation can be performed effectively and safely by using this EUS-guided needle electrode.

Cancer is one of the main diseases that threaten the health of human.In order to increase the cure rate of cancer,the accurate therapy of cancer must be developed speedily.The most effective method for curing cancer is intensity modulated radiation therapy(IMRT),which can increase the local control rate of cancer and decrease complications of tissues.IMRT is considered to be an important breakthrough in cancer therapy.The dose produced by it is better than 3D-CRT and can achieves better results of therapy,which has been confirmed in the clinical therapies of head cancer,neck cancer,prostate cancer,breast cancer,cervical cancer and pancreas cancer etc.The developing course of IMRT,the methods of intensity modulation,the enforcement process of IMRT and the feasibility test of therapy plans are emphatically introduced.

ObjectiveThe efficacy and safety of nitrous oxide-sedated transnasal gastroscopy for high-risk patients of intravenous anesthesia were evaluated. MethodsA total of 157 patients were randomly assigned to the nitrous oxide group ( n =80) and the oxygen group ( n =77). Heart rate, blood oxygen saturation, blood pressure and electrocardiogram were monitored. Complications in both groups were recorded.Satisfaction degrees of patients and endoscopy physicians were evaluated with a questionnaire and visual analog scale (VAS) score. The questionnaire questions for physicians included the procedure evaluation ( steady, ok, unsteady). Patients' questionnaire questions included discomfort (light, moderate, severe), the patients' tolerance ( fine, moderate, weak) and the patients' willingness to undergo a second procedure. Statistical analysis was performed between the two groups. ResultsSix of the toal 157 patients were removed because of the operation failure (difficulty in access to nasal cavity in 5 patients and nose bleeding in one patient), 151 patients underwent the transnasal gastroscopy successfully and completed the questionnaires. In experimental group, there were 37 males and 41 females (mean age was 67.7 years, ranging 16-88 years, 7 patients were grade 1 of ASA, 61 were grade 2, and 11 were grade 3). In the control group, there were 36 males and 37 females (mean age was 67.9 years, ranging 17-86 years, 6 patients were grade 1 of ASA, 57 were grade 2, and 9 were grade 3). There was no differences in sex, average age and ASA grade between the two groups (P ＞ 0. 05 ). There was no difference in the mean operation time between the two groups, either (200. 1 s vs 200. 3 s) ( P ＞ 0. 05 ). There were no significant differences between the two groups in changes of blood oxygen saturation, blood pressure, electrocardiogram and complication rates ( P ＞ 0. 05 ).Both physicians' and patients' positive evaluations of the experimental group were more than that of the control (P ＜ 0. 05 ), while physicians' and patients' negative evaluations of the experimental group were less than the control (P ＜0. 05). VAS of physicians' satisfaction in the experimental group was higher than that of the control group (84 vs 70, t =14. 67, P ＜ 0. 05), and VAS of patients' satisfaction in the experimental group was superior to the control group (82 vs 71, t =11.56, P ＜ 0. 05). The number of patients wiring to undergo a second procedure in the experimental group was higher than that of the control (89. 7％ vs 69. 9％, P ＜ 0. 05). ConclusionNitrous oxide-sedated transnasal endoscopy is an effective and safe procedure for high risk patients of intravenous anesthesia.

ObjectiveTo assess the diagnostic value of EUS for pancreatic neuroendocrine tumors.MethodsClinical data of 26 patients with final diagnosis of pancreatic neuroendocrine tumors,who had underwent EUS and EUS-FNA,were retrospectively analyzed.Results On EUS,pancreatic neuroendocrine tumors presented as hypoechoic masses with clear margins and rich blood flow.Of the 26 pancreatic lesions,3 were in the head,2 in unicate process,2 in neck,11 in body and 8 in tail.The tumors presented with function in 16 ( mean size 9 mm),and on function in 10 ( mean size 29 mm).EUS-FNA yeilded positive results in 22 patients and negative in 4.The accuracy rate of EUS for preoperative localization was 100％ in 23 patients who underwent surgery.ConclusionEUS can provide accurate preoperative localization and pathologic evidence for pancreatic neuroendocrine tumors.

Objective To determine the power-time-ablation scope correlogram of a water-cooled single needle electrode radiofrequency (RF) ablation system and to establish a theoretical basis for its practical application.Methods RF ablations were performed using a water-cooled single needle electrode radiofrequency ablation system developed by the authors using fresh ox liver as well as liver and muscles of healthy adult New Zealand white rabbits.The temperature of the ablation area was monitored using a multichannel thermometric system.The maximum ablation scope was determined by detecting the rim at which the temperature was no less than 50 °C.The specific absorption rate (SAR) of the isolated liver tissue was calculated.Results In the treatment voltage range of 100-130V,the process was smooth and steady.No impedance variation was obvious.The maximum diameter of a single ablation was 51 cm.With the treatment voltage at 140-170 V,a larger ablation area could be reached in less time,but eventually the impedance began to increase while the ablation area was no longer expanded.When the treatment voltage reached the range of 180-200 V the impedance almost always increased rapidly out of limits,and the treatment system stopped automatically.The measured SAR value was consistent with the theoretical value.Pathology confirmed that both liver tissue and muscle tissue manifested typical coagulative necrosis.Conclusions The power amplifier,cooling,thermometric and control sections of the RF ablation system worked stably,and the practical ablation effect met the design and clinical treatment requirements.

Objective To evaluate the long-term safety and efficacy of domestic Firebird rapamycin-eluting stent in treatment of patients with coronary artery disease (CAD). Methods The 465 patients with CAD received percutaneous interventional therapy with domestic Firebird or imported Cypher rapamycin-eluting stent based on patients' will and they were followed up for more than 24 months. Results The 321 cases in Firebird group were followed up for (45.3 ±11.1)months, with 166 cases (51.7%) received reexamination by coronary angiography. The 144 patients in Cypher group were followed up for (46.1 ± 12. 1) months, with 82 patients (56.3%) received reexamination by coronary angiography. At the termination of follow-up, there were no significant differences in all-cause death (7.8% vs. 7.6 %, x2 = 1.32, P = 0. 250), cardiac death (5.9% vs.5.6%, x2 =0. 02, P=0. 877), acute myocardial infarction (2.8% vs. 3.4%, x2 =0. 15, P=0. 697),cardiovascular-cause rehospitalization (29.6% vs. 31.9 %, x2 =0.26, P=0. 610), acute and subacute thrombosis events (0.9% vs. 1.3%, x2 =0.19, P=0.661), late thrombotic events (1.2% vs.1.3%, x2 =0. 02, P=0. 900) and target lesion revascularization (3.4% vs. 4.2%, x2 =0. 15, P=0. 694) between two groups. Conclusions Domestic Firebird rapamycin-eluting stent has the same or similar long-term safety and efficacy with imported Cypher rapamycin-eluting stent.

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 ensure the stability of electronic data capture(EDC)system in drug clinical trials and to improve the quality of drug clinical trials. METHODS:The quality control system for EDC system was established and introduced from the formulation of quality control process,establishment of data standard,trial project management,daily management,trial project design,system operation,system function,etc. RESULTS & CONCLUSIONS:Data standard have been achieved through estab-lishing EDC quality control system by our hospital based on attributable,legible,contemporaneous,original and accurate principle. The management of trial project and daily management are conducted through data registration,staff training,the formulation of da-ta management plan,fault emergency treatment,database backup;multiple verification of support data,data lock and export,trial report autogeneration and other functions have been realized by formulating related standard operation instruction,program file,op-eration manual and quality record. Those aspects improve facticity,accuracy and integrality of data in clinical trials,and lay a foun-dation for further data mining.

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 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).